According to new research, the asteroid that hit Earth and caused the mass extinction that wiped out the dinosaurs also caused an earthquake that rocked the planet for weeks or even months. A space rock that was 6 miles wide that is now known as the Chicxulub impactor collided with Earth about 66 million years ago off the coast of the Gulf of Mexico. The Cretaceous-Paleogene (K-Pg) mass extinction event, which resulted in the extinction of three-quarters of all species on Earth and left its mark scattered throughout the geological record, was brought about by the asteroid impact and its aftermath. According to recent research, the impact also caused a “mega earthquake” that released energy equal to 1023 joules, which is about 50,000 times more energy than the magnitude 9.1 earthquake that struck Sumatra in 2004.
Hermann Bermdez, a geologist at Montclair State University in New Jersey, measured the size of the earthquake caused by the Chicxulub impact by going to places in Texas, Alabama, and Mississippi where the K-Pg mass extinction is still visible.
In addition, he included his own earlier research on the consequences of the asteroid impact in Colombia and Mexico. The geologist discovered layers of sediment containing spherule deposits on Gorgonilla Island in Columbia, which is about 1,900 miles (3,000 km) from the Chicxulub impact site.
Spherules, which are tiny glass beads about the size of a sand grain (about 1 millimeter), are created when a large impact melts material from the Earth’s crust and expels it into the atmosphere, where it cools to form glass beads before falling back to Earth. In the same sediments where the spherules were found, Bermdez also found tektites and microtektites, which are pieces that would have been thrown into the air when an asteroid hit.
Spherules and tektites discovered near Gorgonilla Island’s coast provided information about what transpired on the seafloor about 1.25 miles (2 km) beneath the surface during the time of the asteroid impact. Layers of mud and sandstone as deep as 33 to 50 feet (10 to 15 meters) below the ocean floor were bent as the Chicxulub impactor struck the planet. According to Bermudez, the impact-induced shaking is what resulted in the deformation that is still visible in the outcrops today.
The faults and deformations that are the geologic signature of this shaking persist up until the layers of sediment that are rich in spherules. The layers had to have formed after the impact, but because it would have taken some time for them to build up, Bermdez surmises that the impact’s initial shaking persisted for weeks or even months.
In a statement, Bermdez said, “The section I found on Gorgonilla Island is a fantastic place to study the K-Pg boundary because it is one of the best-preserved and it is located deep in the ocean, so it was not affected by tsunamis”.
In the geological record of Mexico, Bermdez also discovered evidence of a mega-earthquake caused by the Chicxulub impact. There, he found the liquefaction signature, which is what happens when a lot of shaking makes water-soaked sediments flow like liquid.
Bermudez discovered faults and cracks at the locations in Mississippi, Alabama, and Texas that were probably related to the massive earthquake brought on by the Chicxulub impact. A number of outcrops revealed evidence of deposits from massive tsunami waves that were also caused by the large asteroid’s impact on Earth.
